A wiring harness comprises a large number of wires of different length and thickness arranged to connect a plurality of relatively remote electrical devices. Such a harness is used for example in an automobile. Typically the harness will have a central trunk region, through which many of the wires pass, and a large number of branches having relatively few wires. Automobile wiring harnesses can be very complex, with a core region of e.g. 30-50 individual wires, and 20-30 branches of different lengths and thicknesses.
The manufacture of wiring harnesses is relatively labour intensive. The wires are placed one by one on an assembly template, and when complete the individual wires are bound with tape to form the harness. Since the harness includes many wires, it is desirable to temporarily retain each wire in a clip as it is added to the template; in this way the wires are retained in the desired pattern, and individual wires cannot escape from the template. Such clips should permit the attachment of individual wires and removal of the completed harness with maximum speed and minimum effort. Preferably the clip should be no larger than the diameter of the completed harness so as to facilitate tight binding of the wires.
JP-4-61817 discloses a rigid fork with two legs each having an end cap with a resilient arm. These arms are directed towards each other to substantially close the opening of the fork. Wires are snapped one at a time past the arms into the fork for temporary retention. This device has the disadvantage that the caps can be pulled off the fork legs as the completed harness is pulled out of the fork. Furthermore the arms tend to restrict the fork opening when they are bent as the harness is released, and thus the fork must be oversize if ease of use is to be maintained. As noted above, an oversize fork does not facilitate tight binding of the wires, and has the disadvantage of taking up excessive space which prevents several forks being placed close together. A single arm embodiment is also disclosed in this prior document, but the same disadvantages arise.
JP-5-17853 discloses a fork having a fixed leg, and a pivoted leg biased towards the fixed leg by a spring. In the normal state the opening of the fork is not completely closed, leading to the possibility that individual wires will escape. The pivoted leg allows the completed harness to be removed with ease, but the clip is excessively complicated, rather expensive and somewhat slow to release.
JP-9-11252 discloses a fork in which both legs are pivoted on a stand, and biased by a spring to a completely closed condition This fork is completely closed in the normal condition and will thus retain individual wires securely. However the construction is somewhat complex and expensive, and the fork has a wide lateral extent which may restrict operability in the case where several clips must be placed close together.
The present invention aims to provide an improved device for temporarily restraining wires of a harness and which overcomes the problems of the prior art.